Sewing-machine shuttle



Nov. 26, 1929. R. L. HAM I 1,737,418

SEWING MACHINE SHUTTLE Filed Nov. 12. 1928 Patented Nov. 26,

.nonnn'r L. HAM, or BOSTON, massacrmsnrrs, assronon To s'ommir THREAD coinrm, or ast]: namr'rou, connnc'rrocr, A ooitronarron or MAINE snwme-macnrnn SHUTTLE Application filed November 12, 1928. Serial No. 818,640.

This invention relates to 'a shuttle having I a bobbin chamber adapted to contain a headless bobbin composed of a co tube and a thread mass universally woun thereon, the ends of the bobbin beingformed entirely by the ends of the thread mass and'tube, no heads covering the ends of the thread mass being provided as component parts of the bobb1n.-

The chief obiect of the invention is to provide a shutt e having simple means for centrally confining a headless bobbin in the bobbin chamber and permitting'such rotation of the bobbin as may be required by the call of the stitch-forming mechanism for thread, without permitting objectionably loose or free rotation.

Another object is to permit convenient inspection of the thread mass at any time, so that an operator may readily learn when replenishment is required.

Other objects will hereinafter ap ear.

Of the accompanying drawings orming a part of this specification- Figure 1 is a side view the inner side of a shuttle embodying the invention.

Figure 2 is an enlarged section on line 2-2 of Figure 1, the bobbin chamber being closed.

Figure 3 is a view similar to Figure 2,

showing the bobbin chamber opened, and indicating by dotted and full lines the. operation of securing the disks hereinafter described to the body members of the shuttle.

Figure 4 is a view similar to Fi ure 2, omitting the spring hereinafter descri ed.

Figure 5 shows in section a headless bobbin.

Figure 6 is a section on line 6-6 of Fig-,-- ure 3, and a plan view of parts below said line.

Figure 7 is a side view of one of the disks shown by Figures 1, 3 and 4.

Figure 8 is a section on line 88 of Figure Figure 9 1s a view similar to Figure 7,

I showing a modification.

The same reference characters indicate the same parts in all of the figures.

The headless bobbin shown separately by looking toward Figure 4, is composed wholly of a copttube 12, and a thread mass 13, universally, wound thereon, the thread mass beingcompressed l to impart to its'ends the crowning-or bulging form shown by Figure 4.

he shuttle comprises body members 14 and 15, which are referably members of the bod of the well nown Singer IM shuttle, sai members being hinged together at 16, so that the body is adapted to be opened, as shown by. Figure 3,, to receive the bobbin,

and closed, as shown by Figure 2, to confine the bobbin. v The member 14 is provided with the usual spring bar 17, fixed at one end to the mem-' ber 14, and bearing ieldingly at its opposite end on a portion 0i the member 15, the bar being adapted to hold the members Hand 15 either closed together or separated.

The body members are provided with coinciding circular openings 18, collectively forming the divided circular wall of the bobbin chamber, and'inwardly projecting flanges 19, forming narrow annular-seats at opposite ends of the chamber.

The shuttle is characterized by two smooth surfaced heads 20, which are normally flat and resiliently flexible, the material of the headsibeing preferably transparent sheet celluloid, which has suitable resilient flexibility and is adapted by its transparence to permit inspection of the thread mass of a bobbin confinedin the chamber, and by the smoothness of its surfaces to permit a regulated r0 tation of the bobbin. The heads are preferably discoidal, as shown by Figure 6, and

the diameter of each is somewhat greater the inner head may be slightly spaced from therefrom and prevent undesira 1y free rota:

tion of the bobbin. A shuttle of this type is usuall provided with'a pressing spring 22, attac edat 23 to the body member 14:, and having a free end projecting into the bobbin chamber, and adapted to exert pressureon the inner end of a bobbin in'the chamber, and press the outer end of the bobbin against the outer flange 19, on the member 15, the bobbin usually having heads secured to its ends, and constituting component parts of the bobbin.

The flexibility of the heads-20 is ac that the pressure of the spring 22 may be transmitted through the central portion of the inner head 20, to the bobbin, the, said head being inwardly flexed by the spring, so that the two heads exert the desired regulated pressure on the two ends of the bobbin.

When the bobbin is of minimum length,

the inner flange 19, as shown by Figure 2,

r the outer head being seated on the outer flange.

If the bobbin is of maximum length, eachof the heads 20 may be seated on a flange 19, and the spring 22 may be omitted, as

shown .by Figure 4. I prefer, however, to employ the spring 22, because of liability of i slight variations in the length of different for by the spring.

bobbins, these variations being compensated It will be seen that the heads 20 of re- I I siliently flexible material, such as sheet celluloid, may be made very thin, so that the headindicated by Figure9, so that their peripheries are not continuous'circles.

I claim:

A shuttle foruse with a ready-wound headlessbobbin, having crowningends and composed of a cop tubeand a thread wound thereon,-said shuttle comprising relatively movable body members having coinciding openin 's collectively forming the divided wall at a circular bobbin chamber and annular inwardly projecting flanges forming annular seats at opposite ends of said chamber, one member eing movable relative to the. other to open and close the chamber, the shuttle being characterized by smooth, re siliently flexible, transparent heads, adapted to confine a bobbin in the chamber and contact yieldably with the ends of the bobbin,

so that the bobbin is rotatable when confined between the heads, its rotation being yield- Ingly opposed thereby, said heads being frictionally engaged with the chamber wall to prevent rotation and displacement of the heads, and impart thereto a crowning form, the heads being provided with central, convex, opposed, struck-out portions adapted to enter the ends of the co tube to centralize and permit rotation of t e bobbin, a spring presser fixed to one of the body members and adapted to exert inward pressure on the head engaged with said member and inwardly flex the central portion of said head to increase its pressure on the bobbin.

In testimony whereof I have afiixed my ROBERT L. HAM.

signature.

less bobbin may have a greater yardage of thread than is possible when the bobbin includes heads as component parts thereof, such heads occupying space ln-the bobbin chamber which in the improved shuttle contains thread.

The bosses 21 have convex surfaces projecting into the ends of the cop tube 12, and sloping from the inner surfaces of the heads, so that in case a portion of the thread drops on. the marginal portion of the inner head and is drawn between said head and the thread mass 13, such portion may passentirely across the inner head and the boss thereon, withoiit being obstructed or jammed between the head and the mass.

Portions of the heads may be cut away, as 

